feat: fallback model range slider with live label, model-changed event

- Added model-changed event: backend emits it on fallback, frontend updates tab keyId/modelId
- Range slider embedded inside active agent card when >1 model configured
- Live label updates on drag (oninput), backend call only on release (onchange)
- Slider auto-positions when fallback occurs via model-changed WS event

1 files changed, 1 insertions, 0 deletions

diff --git a/packages/core/src/types/index.ts b/packages/core/src/types/index.ts
index b17a720..1c3090f 100644
--- a/packages/core/src/types/index.ts
+++ b/packages/core/src/types/index.ts
@@ -38,6 +38,7 @@ export type AgentEvent =
 	| { type: "shell-output"; data: string; stream: "stdout" | "stderr" }
 	| { type: "error"; error: string; statusCode?: number }
 	| { type: "notice"; message: string }
+	| { type: "model-changed"; keyId: string; modelId: string }
 	| { type: "done"; message: ChatMessage }
 	| { type: "task-list-update"; tasks: TaskItem[] }
 	| { type: "config-reload" }